Risk-Aware Motion Planning in Partially Known Environments
This work addresses safety planning for robots in dangerous, partially known environments, representing an incremental improvement by adapting existing methods to incorporate risk awareness.
The paper tackled the problem of motion planning for robots in hazardous environments with unknown processes by using Gaussian process regression to model risks and integrating risk metrics into planning algorithms, resulting in algorithms that successfully avoid high-risk areas in simulations.
Recent trends envisage robots being deployed in areas deemed dangerous to humans, such as buildings with gas and radiation leaks. In such situations, the model of the underlying hazardous process might be unknown to the agent a priori, giving rise to the problem of planning for safe behaviour in partially known environments. We employ Gaussian process regression to create a probabilistic model of the hazardous process from local noisy samples. The result of this regression is then used by a risk metric, such as the Conditional Value-at-Risk, to reason about the safety at a certain state. The outcome is a risk function that can be employed in optimal motion planning problems. We demonstrate the use of the proposed function in two approaches. First is a sampling-based motion planning algorithm with an event-based trigger for online replanning. Second is an adaptation to the incremental Gaussian Process motion planner (iGPMP2), allowing it to quickly react and adapt to the environment. Both algorithms are evaluated in representative simulation scenarios, where they demonstrate the ability of avoiding high-risk areas.